Investigate Replacing Tar with Dar

Currently Freezer uses Gnu Tar to do incremental backups. Restore fails if the user has removed a directory and then renamed another directory to the removed directory. Dar handles this case. Should investigate if Dar would be a suitable replacement for Tar.

Here are the steps to reproduce problem with tar.

mkdir backup
mkdir backup/dir1
mkdir backup/dir2
echo "aa" > backup/dir1/dir1-file1
echo "aa" > backup/dir2/dir2-file1
tar --create --file=backup.tar --listed-incremental=./listed-incr backup
rm -rf backup/dir2
mv backup/dir1 backup/dir2
tar --create --file=backup.2.tar --listed-incremental=./listed-incr backup
tar --extract --listed-incrementa=/dev/null --file backup.tar
tar --extract --listed-incrementa=/dev/null --file backup.2.tar

tar: Cannot rename ‘backup/dir1’ to ‘backup/dir2’: Directory not empty
tar: Exiting with failure status due to previous errors